Ms. Swarns links the problems in Mr. Buck’s death-penalty case, where a psychologist testified that he was more likely to commit another violent offense because he was black, to broader racial injustices in the criminal law:

Predictions of future dangerousness are absurd, and then to be put in a capital punishment box which is already so contaminated by racial bias. The introduction of evidence linking race to dangerousness — like that which was presented in the Duane Buck case — was an inevitable product of future dangerousness in the capital punishment system in Texas. Because the Texas death penalty system was already so contaminated and corrupted by racial bias, the Duane Buck death sentence was a predictable outcome of that mess. …

In McCleskey v. Kemp the Supreme Court was asked to consider the statistical evidence of racial discrimination in death sentences reached by one study. The analysis found that defendants accused of killing white victims were 4.3 times more likely to receive the death penalty than defendants accused of killing black victims. The Supreme Court argued that racial discrimination has to be established in individual cases, not in the aggregate. Ironically, the court was perfectly willing to accept weak statistical arguments involving future dangerousness but to reject strong statistical arguments involving race and sentencing. …

The business of predicting future dangerousness without becoming corrupted by the various factors that are so tied to human functioning is impossible. It’s an absurd requirement. As a prerequisite for a death sentence, it’s insane.

Professor Mark Osler, writing for the Marshall Project, shows how the prosecutor-run Department of Justice often works to stymie criminal justice reform. He illustrates his point with this appealing hypothetical:

Imagine an incoming president of the United States announcing that he or she would take advice on criminal justice matters exclusively from a Federal Defender’s office. Moreover, the new chief executive intends to put the defenders in charge of federal prisons, forensic science, and the clemency process. After all, the president might argue, the defenders understand federal criminal law from the ground up, have a rich understanding of the social conditions that lead to criminal behavior, and are the federal attorneys most responsible for ensuring individual Constitutional protections.

People would be outraged. Critics would complain that the defenders represent only one part of the justice system, and are inherently biased because their work in the courts is always on behalf of the accused.

Yet, somehow, the mirror image of that situation is our reality and goes largely unchallenged.

Judge Jed Rakoff, talking with Judge Posner and Slate’s Joel Cohen, describes the Fifth Amendment right to remain silent as one example of the tension between truth and justice in American criminal law:

[O]ur Constitution allows a defendant to remain silent, even though that may in some sense impede the search for the truth.

The historic reason for this restriction is that in its absence, the government is easily persuaded to use torture to extract confessions—which is what happened in the English Star Chamber that gave rise to the Fifth Amendment privilege against self-incrimination. But is also commonplace today in legal systems like China’s, that don’t have such a privilege, and, at least for a time, was utilized in places like America’s Guantanamo Bay prison that were supposedly outside the reach of the Constitution.

While the Fifth Amendment is actually designed in part to advance the truth by guarding against coerced false confessions, it also serves the independent purpose of putting a check on government practices that most people consider repugnant regardless of their results. In short, while a legal system built on untruths is inherently unjust, truth is not the only requirement for achieving justice.